U.S. patent application number 14/695049 was filed with the patent office on 2016-07-28 for optical imaging lens and electronic device comprising the same.
The applicant listed for this patent is Shih-Han Chen, Shan Huang, Huabin Liao. Invention is credited to Shih-Han Chen, Shan Huang, Huabin Liao.
Application Number | 20160216478 14/695049 |
Document ID | / |
Family ID | 53693292 |
Filed Date | 2016-07-28 |
United States Patent
Application |
20160216478 |
Kind Code |
A1 |
Chen; Shih-Han ; et
al. |
July 28, 2016 |
OPTICAL IMAGING LENS AND ELECTRONIC DEVICE COMPRISING THE SAME
Abstract
An optical imaging lens set includes an aperture stop, a first
lens element to a sixth lens element from an object side toward an
image side along an optical axis. The first lens element has an
image-side surface with a convex portion in a vicinity of its
periphery. The second lens element has an image-side surface with a
concave portion in a vicinity of the optical axis and a convex
portion in a vicinity of its periphery. The third lens element is
made of plastic. The fourth lens element has an image-side surface
with a concave portion in a vicinity of its periphery. The fifth
lens element is made of plastic. The sixth lens element is made of
plastic and has an object-side surface with a concave portion in a
vicinity of the optical axis.
Inventors: |
Chen; Shih-Han; (Taichung
City, TW) ; Liao; Huabin; (Taichung City, TW)
; Huang; Shan; (Taichung City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Chen; Shih-Han
Liao; Huabin
Huang; Shan |
Taichung City
Taichung City
Taichung City |
|
TW
TW
TW |
|
|
Family ID: |
53693292 |
Appl. No.: |
14/695049 |
Filed: |
April 24, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B 13/0015 20130101;
G02B 9/62 20130101; G02B 9/64 20130101; G02B 13/0045 20130101; G02B
13/002 20130101; G02B 5/005 20130101; G02B 27/0025 20130101; G02B
13/001 20130101; G02B 3/04 20130101; G02B 13/18 20130101 |
International
Class: |
G02B 13/00 20060101
G02B013/00; H04N 5/225 20060101 H04N005/225; G02B 9/62 20060101
G02B009/62 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 23, 2015 |
CN |
201510034254.X |
Claims
1. An optical imaging lens set, from an object side toward an image
side in order along an optical axis comprising: a first lens
element, a second lens element, a third lens element, a fourth lens
element, a fifth lens element and a sixth lens element, said first
lens element to said sixth lens element each having an object-side
surface facing toward the object side as well as an image-side
surface facing toward the image side, wherein: said first lens
element has an image-side surface with a convex portion in a
vicinity of its periphery; said second lens element has an
image-side surface with a concave portion in a vicinity of said
optical axis and a convex portion in a vicinity of its periphery;
said third lens element is made of plastic; said fourth lens
element has an image-side surface with a concave portion in a
vicinity of its periphery; said fifth lens element is made of
plastic; and said sixth lens element is made of plastic and has an
object-side surface with a concave portion in a vicinity of said
optical axis, and said optical imaging lens set exclusively has
said first lens element, said second lens element, said third lens
element, said fourth lens element, said fifth lens element and said
sixth lens element with refractive power.
2. The optical imaging lens set of claim 1, wherein the effective
focal length EFL of said optical imaging lens set and a thickness
T.sub.1 of said first lens element along said optical axis satisfy
a relationship EFL/T.sub.1.ltoreq.7.5.
3. The optical imaging lens set of claim 2, wherein an air gap
G.sub.34 between said third lens element and said fourth lens
element along said optical axis and a thickness T.sub.6 of said
sixth lens element along said optical axis satisfy a relationship
T.sub.6/G.sub.34.ltoreq.4.
4. The optical imaging lens set of claim 2, wherein a total
thickness ALT of said first lens element, said second lens element,
said third lens element, said fourth lens element, said fifth lens
element and said sixth lens element along said optical axis, and an
air gap G.sub.34 between said third lens element and said fourth
lens element along said optical axis satisfy a relationship
ALT/G.sub.34.ltoreq.19.
5. The optical imaging lens set of claim 2, wherein a distance BFL
between said image-side surface of said sixth lens element to an
image plane and a thickness T.sub.2 of said second lens element
along said optical axis satisfy a relationship
BFL/T.sub.2.ltoreq.5.77.
6. The optical imaging lens set of claim 1, wherein a thickness
T.sub.2 of said second lens element along said optical axis and a
thickness T.sub.6 of said sixth lens element along said optical
axis satisfy a relationship 0.45.ltoreq.T.sub.2/T.sub.6.
7. The optical imaging lens set of claim 6, wherein a thickness
T.sub.1 of said first lens element along said optical axis, and a
thickness T.sub.5 of said fifth lens element along said optical
axis satisfy a relationship T.sub.5/T.sub.1.ltoreq.1.4.
8. The optical imaging lens set of claim 1, wherein the effective
focal length EFL of said optical imaging lens set and a thickness
T.sub.2 of said second lens element along said optical axis satisfy
a relationship EFL/T.sub.2.ltoreq.16.
9. The optical imaging lens set of claim 8, wherein a thickness
T.sub.1 of said first lens element along said optical axis, and a
thickness T.sub.3 of said third lens element along said optical
axis satisfy a relationship 1.ltoreq.T.sub.1/T.sub.3.
10. The optical imaging lens set of claim 1, wherein a total
thickness ALT of said first lens element, said second lens element,
said third lens element, said fourth lens element, said fifth lens
element and said sixth lens element along said optical axis, and a
thickness T.sub.1 of said first lens element along said optical
axis satisfy a relationship ALT/T.sub.1.ltoreq.7.
11. The optical imaging lens set of claim 10, wherein the effective
focal length EFL of said optical imaging lens set and an air gap
G.sub.34 between said third lens element and said fourth lens
element along said optical axis satisfy a relationship
EFL/G.sub.34.ltoreq.25.2.
12. The optical imaging lens set of claim 10, wherein the sum of
all five air gaps AAG between each lens element from said first
lens element to said sixth lens element along the optical axis, an
air gap G.sub.45 between said fourth lens element and said fifth
lens element along said optical axis and an air gap G.sub.56
between said fifth lens element and said sixth lens element along
said optical axis satisfy a relationship
2.41.ltoreq.AAG/(G.sub.45+G.sub.56).
13. The optical imaging lens set of claim 1, wherein a thickness
T.sub.5 of said fifth lens element along said optical axis and a
thickness T.sub.6 of said sixth lens element along said optical
axis satisfy a relationship T.sub.5/T.sub.6.ltoreq.2.08.
14. The optical imaging lens set of claim 13, wherein the effective
focal length EFL of said optical imaging lens set and a thickness
T.sub.4 of said fourth lens element along said optical axis satisfy
a relationship EFL/T.sub.4.ltoreq.9.38.
15. The optical imaging lens set of claim 1, wherein a thickness
T.sub.4 of said fourth lens element along said optical axis and a
thickness T.sub.5 of said fifth lens element along said optical
axis satisfy a relationship T.sub.5/T.sub.4.ltoreq.1.29.
16. The optical imaging lens set of claim 1, wherein a total
thickness ALT of said first lens element, said second lens element,
said third lens element, said fourth lens element, said fifth lens
element and said sixth lens element along said optical axis, and a
thickness T.sub.4 of said fourth lens element along said optical
axis satisfy a relationship ALT/T.sub.4.ltoreq.6.5.
17. An electronic device, comprising: a case; and an image module
disposed in said case and comprising: an optical imaging lens set
of claim 1; a barrel for the installation of said optical imaging
lens set; a module housing unit for the installation of said
barrel; and an image sensor disposed at an image side of said
optical imaging lens set.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Chinese Patent
Application No. 201510034254.X, filed on Jan. 23, 2015, the
contents of which are hereby incorporated by reference in their
entirety for all purposes.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to an optical
imaging lens set and an electronic device which includes such
optical imaging lens set. Specifically speaking, the present
invention is directed to a shorter optical imaging lens set of six
lens elements and a shorter electronic device which includes such
optical imaging lens set of six lens elements.
[0004] 2. Description of the Prior Art
[0005] In recent years, the popularity of mobile phones and digital
cameras makes the sizes of various portable electronic products
reduce quickly, and so does that of the photography modules. The
current trend of research is to develop an optical imaging lens set
of a shorter length with uncompromised good quality. With the
development and shrinkage of a charge coupled device (CCD) or a
complementary metal oxide semiconductor element (CMOS), the optical
imaging lens set installed in the photography module shrinks as
well to meet the demands. However, good and necessary optical
properties, such as the system aberration improvement, as well as
production cost and production feasibility should be taken into
consideration, too.
[0006] Most conventional optical imaging lens sets are made of four
lens elements. Due to fewer lens elements, the total length of the
optical imaging lens set would be shorter. With the demanding
requirements of products of higher specifications, the demands for
the pixels and quality optical imaging lens sets are drastically
higher and higher, products of higher specifications are needed,
for example, an optical imaging lens set of six lens elements. U.S.
Pat. No. 7,663,814 and U.S. Pat. No. 8,040,618 all disclose a total
length of 21 mm or larger. In particular, U.S. Pat. No. 8,179,616
even has a total length of 11 mm, which is not ideal for the size
reduction of the portable devices. Therefore, how to reduce the
total length of a photographic device, but still maintain good
optical performance, is an important objective to research.
SUMMARY OF THE INVENTION
[0007] In light of the above, the present invention proposes an
optical imaging lens set that is lightweight, has a low production
cost, has an enlarged half of field of view, has a high resolution
and has high image quality. The optical imaging lens set of six
lens elements of the present invention from an object side toward
an image side in order along an optical axis has an aperture stop,
a first lens element, a second lens element, a third lens element,
a fourth lens element, a fifth lens element and a sixth lens
element. Each lens element has an object-side surface facing toward
an object side as well as an image-side surface facing toward an
image side.
[0008] The first lens element has an image-side surface with a
convex portion in a vicinity of its periphery. The second lens
element has an image-side surface with a concave portion in a
vicinity of the optical axis and a convex portion in a vicinity of
its periphery. The third lens element is made of plastic. The
fourth lens element has an image-side surface with a concave
portion in a vicinity of its periphery. The fifth lens element is
made of plastic. The sixth lens element is made of plastic and has
an object-side surface with a concave portion in a vicinity of the
optical axis. The optical imaging lens set exclusively has the
first lens element, the second lens element, the third lens
element, the fourth lens element, the fifth lens element and the
sixth lens element with refractive power.
[0009] In the optical imaging lens set of sixth lens elements of
the present invention, the effective focal length EFL of the
optical imaging lens set and a thickness T.sub.1 of the first lens
element along the optical axis satisfy a relationship
EFL/T.sub.1.ltoreq.7.5.
[0010] In the optical imaging lens set of sixth lens elements of
the present invention, an air gap G.sub.34 between the third lens
element and the fourth lens element along the optical axis and a
thickness T.sub.6 of the sixth lens element along the optical axis
satisfy a relationship T.sub.6/G.sub.34.ltoreq.4.
[0011] In the optical imaging lens set of sixth lens elements of
the present invention, a total thickness ALT of the first lens
element, the second lens element, the third lens element, the
fourth lens element, the fifth lens element and the sixth lens
element along the optical axis, and an air gap G.sub.34 between the
third lens element and the fourth lens element along the optical
axis satisfy a relationship ALT/G.sub.34.ltoreq.19.
[0012] In the optical imaging lens set of sixth lens elements of
the present invention, a distance BFL between the image-side
surface of the sixth lens element to an image plane and a thickness
T.sub.2 of the second lens element along the optical axis satisfy a
relationship BFL/T.sub.2.ltoreq.5.77.
[0013] In the optical imaging lens set of sixth lens elements of
the present invention, a thickness T.sub.2 of the second lens
element along the optical axis and a thickness T.sub.6 of the sixth
lens element along the optical axis satisfy a relationship
0.45.ltoreq.T.sub.2/T.sub.6.
[0014] In the optical imaging lens set of sixth lens elements of
the present invention, a thickness T.sub.1 of the first lens
element along the optical axis, and a thickness T.sub.5 of the
fifth lens element along the optical axis satisfy a relationship
T.sub.5/T.sub.1.ltoreq.1.4.
[0015] In the optical imaging lens set of sixth lens elements of
the present invention, the effective focal length EFL of the
optical imaging lens set and a thickness T.sub.2 of the second lens
element along the optical axis satisfy a relationship
EFL/T.sub.2.ltoreq.16.
[0016] In the optical imaging lens set of sixth lens elements of
the present invention, a thickness T.sub.1 of the first lens
element along the optical axis, and a thickness T.sub.3 of the
third lens element along the optical axis satisfy a relationship
1.ltoreq.T.sub.1/T.sub.3.
[0017] In the optical imaging lens set of sixth lens elements of
the present invention, a total thickness ALT of the first lens
element, the second lens element, the third lens element, the
fourth lens element, the fifth lens element and the sixth lens
element along the optical axis, and a thickness T.sub.1 of the
first lens element along the optical axis satisfy a relationship
ALT/T.sub.1.ltoreq.7.
[0018] In the optical imaging lens set of sixth lens elements of
the present invention, the effective focal length EFL of the
optical imaging lens set and an air gap G.sub.34 between the third
lens element and the fourth lens element along the optical axis and
an air gap G.sub.34 between the third lens element and the fourth
lens element along the optical axis satisfy a relationship
EFL/G.sub.34.ltoreq.25.2.
[0019] In the optical imaging lens set of sixth lens elements of
the present invention, the sum of all three air gaps AAG between
each lens element from the first lens element to the sixth lens
element along the optical axis, an air gap G.sub.45 between the
fourth lens element and the fifth lens element along the optical
axis and an air gap G.sub.56 between the fifth lens element and the
sixth lens element along the optical axis satisfy a relationship
2.41.ltoreq.AAG/(G.sub.45+G.sub.56).
[0020] In the optical imaging lens set of sixth lens elements of
the present invention, a thickness T.sub.5 of the fifth lens
element along the optical axis and a thickness T.sub.6 of the sixth
lens element along the optical axis satisfy a relationship
T.sub.5/T.sub.6.ltoreq.2.08.
[0021] In the optical imaging lens set of sixth lens elements of
the present invention, the effective focal length EFL of the
optical imaging lens set and an a thickness T.sub.4 of the fourth
lens element along the optical axis satisfy a relationship
EFL/T.sub.4.ltoreq.9.38.
[0022] In the optical imaging lens set of sixth lens elements of
the present invention, a thickness T.sub.4 of the fourth lens
element along the optical axis and a thickness T.sub.5 of the fifth
lens element along the optical axis satisfy a relationship
T.sub.5/T.sub.4.ltoreq.1.29.
[0023] In the optical imaging lens set of sixth lens elements of
the present invention, a total thickness ALT of the first lens
element, the second lens element, the third lens element, the
fourth lens element, the fifth lens element and the sixth lens
element along the optical axis, and a thickness T.sub.4 of the
fourth lens element along the optical axis satisfy a relationship
ALT/T.sub.4.ltoreq.6.5.
[0024] The present invention also proposes an electronic device
which includes the optical imaging lens set as described above. The
electronic device includes a case and an image module disposed in
the case. The image module includes an optical imaging lens set as
described above, a barrel for the installation of the optical
imaging lens set, a module housing unit for the installation of the
barrel, and an image sensor disposed at an image side of the
optical imaging lens set.
[0025] These and other objectives of the present invention will no
doubt become obvious to those of ordinary skill in the art after
reading the following detailed description of the preferred
embodiment that is illustrated in the various figures and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIGS. 1-5 illustrates the methods for determining the
surface shapes and for determining one region is a region in a
vicinity of the optical axis or the region in a vicinity of its
circular periphery of one lens element.
[0027] FIG. 6 illustrates a first example of the optical imaging
lens set of the present invention.
[0028] FIG. 7A illustrates the longitudinal spherical aberration on
the image plane of the first example.
[0029] FIG. 7B illustrates the astigmatic aberration on the
sagittal direction of the first example.
[0030] FIG. 7C illustrates the astigmatic aberration on the
tangential direction of the first example.
[0031] FIG. 7D illustrates the distortion aberration of the first
example.
[0032] FIG. 8 illustrates a second example of the optical imaging
lens set of six lens elements of the present invention.
[0033] FIG. 9A illustrates the longitudinal spherical aberration on
the image plane of the second example.
[0034] FIG. 9B illustrates the astigmatic aberration on the
sagittal direction of the second example.
[0035] FIG. 9C illustrates the astigmatic aberration on the
tangential direction of the second example.
[0036] FIG. 9D illustrates the distortion aberration of the second
example.
[0037] FIG. 10 illustrates a third example of the optical imaging
lens set of six lens elements of the present invention.
[0038] FIG. 11A illustrates the longitudinal spherical aberration
on the image plane of the third example.
[0039] FIG. 11B illustrates the astigmatic aberration on the
sagittal direction of the third example.
[0040] FIG. 11C illustrates the astigmatic aberration on the
tangential direction of the third example.
[0041] FIG. 11D illustrates the distortion aberration of the third
example.
[0042] FIG. 12 illustrates a fourth example of the optical imaging
lens set of six lens elements of the present invention.
[0043] FIG. 13A illustrates the longitudinal spherical aberration
on the image plane of the fourth example.
[0044] FIG. 13B illustrates the astigmatic aberration on the
sagittal direction of the fourth example.
[0045] FIG. 13C illustrates the astigmatic aberration on the
tangential direction of the fourth example.
[0046] FIG. 13D illustrates the distortion aberration of the fourth
example.
[0047] FIG. 14 illustrates a fifth example of the optical imaging
lens set of six lens elements of the present invention.
[0048] FIG. 15A illustrates the longitudinal spherical aberration
on the image plane of the fifth example.
[0049] FIG. 15B illustrates the astigmatic aberration on the
sagittal direction of the fifth example.
[0050] FIG. 15C illustrates the astigmatic aberration on the
tangential direction of the fifth example.
[0051] FIG. 15D illustrates the distortion aberration of the fifth
example.
[0052] FIG. 16 illustrates a sixth example of the optical imaging
lens set of six lens elements of the present invention.
[0053] FIG. 17A illustrates the longitudinal spherical aberration
on the image plane of the sixth example.
[0054] FIG. 17B illustrates the astigmatic aberration on the
sagittal direction of the sixth example.
[0055] FIG. 17C illustrates the astigmatic aberration on the
tangential direction of the sixth example.
[0056] FIG. 17D illustrates the distortion aberration of the sixth
example.
[0057] FIG. 18 illustrates a seventh example of the optical imaging
lens set of six lens elements of the present invention.
[0058] FIG. 19A illustrates the longitudinal spherical aberration
on the image plane of the seventh example.
[0059] FIG. 19B illustrates the astigmatic aberration on the
sagittal direction of the seventh example.
[0060] FIG. 19C illustrates the astigmatic aberration on the
tangential direction of the seventh example.
[0061] FIG. 19D illustrates the distortion aberration of the
seventh example.
[0062] FIG. 20 illustrates a first preferred example of the
portable electronic device with an optical imaging lens set of the
present invention.
[0063] FIG. 21 illustrates a second preferred example of the
portable electronic device with an optical imaging lens set of the
present invention.
[0064] FIG. 22 shows the optical data of the first example of the
optical imaging lens set.
[0065] FIG. 23 shows the aspheric surface data of the first
example.
[0066] FIG. 24 shows the optical data of the second example of the
optical imaging lens set.
[0067] FIG. 25 shows the aspheric surface data of the second
example.
[0068] FIG. 26 shows the optical data of the third example of the
optical imaging lens set.
[0069] FIG. 27 shows the aspheric surface data of the third
example.
[0070] FIG. 28 shows the optical data of the fourth example of the
optical imaging lens set.
[0071] FIG. 29 shows the aspheric surface data of the fourth
example.
[0072] FIG. 30 shows the optical data of the fifth example of the
optical imaging lens set.
[0073] FIG. 31 shows the aspheric surface data of the fifth
example.
[0074] FIG. 32 shows the optical data of the sixth example of the
optical imaging lens set.
[0075] FIG. 33 shows the aspheric surface data of the sixth
example.
[0076] FIG. 34 shows the optical data of the seventh example of the
optical imaging lens set.
[0077] FIG. 35 shows the aspheric surface data of the seventh
example.
[0078] FIG. 36 shows some important ratios in the examples.
DETAILED DESCRIPTION
[0079] Before the detailed description of the present invention,
the first thing to be noticed is that in the present invention,
similar (not necessarily identical) elements are labeled as the
same numeral references. In the entire present specification, "a
certain lens element has negative/positive refractive power" refers
to the part in a vicinity of the optical axis of the lens element
has negative/positive refractive power calculated by Gaussian
optical theory. An object-side/image-side surface refers to the
region which allows imaging light passing through, in the drawing,
imaging light includes Lc (chief ray) and Lm (marginal ray). As
shown in FIG. 1, the optical axis is "I" and the lens element is
symmetrical with respect to the optical axis I. The region A that
near the optical axis and for light to pass through is the region
in a vicinity of the optical axis, and the region C that the
marginal ray passing through is the region in a vicinity of a
certain lens element's circular periphery. In addition, the lens
element may include an extension part E for the lens element to be
installed in an optical imaging lens set (that is the region
outside the region C perpendicular to the optical axis). Ideally
speaking, no light would pass through the extension part, and the
actual structure and shape of the extension part is not limited to
this and may have other variations. For the reason of simplicity,
the extension part is not illustrated in the following examples.
More, precisely, the method for determining the surface shapes or
the region in a vicinity of the optical axis, the region in a
vicinity of its circular periphery and other regions is described
in the following paragraphs:
1. FIG. 1 is a radial cross-sectional view of a lens element.
Before determining boundaries of those aforesaid portions, two
referential points should be defined first, middle point and
conversion point. The middle point of a surface of a lens element
is a point of intersection of that surface and the optical axis.
The conversion point is a point on a surface of a lens element,
where the tangent line of that point is perpendicular to the
optical axis. Additionally, if multiple conversion points appear on
one single surface, then these conversion points are sequentially
named along the radial direction of the surface with numbers
starting from the first conversion point. For instance, the first
conversion point (closest one to the optical axis), the second
conversion point, and the N.sup.th conversion point (farthest one
to the optical axis within the scope of the clear aperture of the
surface). The portion of a surface of the lens element between the
middle point and the first conversion point is defined as the
portion in a vicinity of the optical axis. The portion located
radially outside of the N.sup.th conversion point (but still within
the scope of the clear aperture) is defined as the portion in a
vicinity of a periphery of the lens element. In some embodiments,
there are other portions existing between the portion in a vicinity
of the optical axis and the portion in a vicinity of a periphery of
the lens element; the numbers of portions depend on the numbers of
the conversion point(s). In addition, the radius of the clear
aperture (or a so-called effective radius) of a surface is defined
as the radial distance from the optical axis I to a point of
intersection of the marginal ray Lm and the surface of the lens
element. 2. Referring to FIG. 2, determining the shape of a portion
is convex or concave depends on whether a collimated ray passing
through that portion converges or diverges. That is, while applying
a collimated ray to a portion to be determined in terms of shape,
the collimated ray passing through that portion will be bended and
the ray itself or its extension line will eventually meet the
optical axis. The shape of that portion can be determined by
whether the ray or its extension line meets (intersects) the
optical axis (focal point) at the object-side or image-side. For
instance, if the ray itself intersects the optical axis at the
image side of the lens element after passing through a portion,
i.e. the focal point of this ray is at the image side (see point R
in FIG. 2), the portion will be determined as having a convex
shape. On the contrary, if the ray diverges after passing through a
portion, the extension line of the ray intersects the optical axis
at the object side of the lens element, i.e. the focal point of the
ray is at the object side (see point M in FIG. 2), that portion
will be determined as having a concave shape. Therefore, referring
to FIG. 2, the portion between the middle point and the first
conversion point has a convex shape, the portion located radially
outside of the first conversion point has a concave shape, and the
first conversion point is the point where the portion having a
convex shape changes to the portion having a concave shape, namely
the border of two adjacent portions. Alternatively, there is
another common way for a person with ordinary skill in the art to
tell whether a portion in a vicinity of the optical axis has a
convex or concave shape by referring to the sign of an "R" value,
which is the (paraxial) radius of curvature of a lens surface. The
R value is commonly used in conventional optical design software
such as Zemax and CodeV. The R value usually appears in the lens
data sheet in the software. For an object-side surface, positive R
means that the object-side surface is convex, and negative R means
that the object-side surface is concave. Conversely, for an
image-side surface, positive R means that the image-side surface is
concave, and negative R means that the image-side surface is
convex. The result found by using this method should be consistent
as by using the other way mentioned above, which determines surface
shapes by referring to whether the focal point of a collimated ray
is at the object side or the image side. 3. For none conversion
point cases, the portion in a vicinity of the optical axis is
defined as the portion between 0-50% of the effective radius
(radius of the clear aperture) of the surface, whereas the portion
in a vicinity of a periphery of the lens element is defined as the
portion between 50-100% of effective radius (radius of the clear
aperture) of the surface.
[0080] Referring to the first example depicted in FIG. 3, only one
conversion point, namely a first conversion point, appears within
the clear aperture of the image-side surface of the lens element.
Portion I is a portion in a vicinity of the optical axis, and
portion II is a portion in a vicinity of a periphery of the lens
element. The portion in a vicinity of the optical axis is
determined as having a concave surface due to the R value at the
image-side surface of the lens element is positive. The shape of
the portion in a vicinity of a periphery of the lens element is
different from that of the radially inner adjacent portion, i.e.
the shape of the portion in a vicinity of a periphery of the lens
element is different from the shape of the portion in a vicinity of
the optical axis; the portion in a vicinity of a periphery of the
lens element has a convex shape.
[0081] Referring to the second example depicted in FIG. 4, a first
conversion point and a second conversion point exist on the
object-side surface (within the clear aperture) of a lens element.
In which portion I is the portion in a vicinity of the optical
axis, and portion III is the portion in a vicinity of a periphery
of the lens element. The portion in a vicinity of the optical axis
has a convex shape because the R value at the object-side surface
of the lens element is positive. The portion in a vicinity of a
periphery of the lens element (portion III) has a convex shape.
What is more, there is another portion having a concave shape
existing between the first and second conversion point (portion
II).
[0082] Referring to a third example depicted in FIG. 5, no
conversion point exists on the object-side surface of the lens
element. In this case, the portion between 0-50% of the effective
radius (radius of the clear aperture) is determined as the portion
in a vicinity of the optical axis, and the portion between 50-100%
of the effective radius is determined as the portion in a vicinity
of a periphery of the lens element. The portion in a vicinity of
the optical axis of the object-side surface of the lens element is
determined as having a convex shape due to its positive R value,
and the portion in a vicinity of a periphery of the lens element is
determined as having a convex shape as well.
[0083] As shown in FIG. 6, the optical imaging lens set 1 of six
lens elements of the present invention, sequentially located from
an object side 2 (where an object is located) to an image side 3
along an optical axis 4, has an aperture stop (ape. stop) 80, a
first lens element 10, a second lens element 20, a third lens
element 30, a fourth lens element 40, a fifth lens element 50, a
sixth lens element 60, a filter 70 and an image plane 71. Generally
speaking, the first lens element 10, the second lens element 20,
the third lens element 30, the fourth lens element 40, the fifth
lens element 50 and the sixth lens element 60 may be made of a
transparent plastic material but the present invention is not
limited to this and each has an appropriate refractive power.
However, the third lens element 30, the fifth lens element 50 and
the sixth lens element 60 are made of a transparent plastic
material. There are exclusively six lens elements, which means the
first lens element 10, the second lens element 20, the third lens
element 30, the fourth lens element 40, the fifth lens element 50
and the sixth lens element 60, with refractive power in the optical
imaging lens set 1 of the present invention. The optical axis 4 is
the optical axis of the entire optical imaging lens set 1, and the
optical axis of each of the lens elements coincides with the
optical axis of the optical imaging lens set 1.
[0084] Furthermore, the optical imaging lens set 1 includes an
aperture stop (ape. stop) 80 disposed in an appropriate position.
In FIG. 6, the aperture stop 80 is disposed between the object side
2 and the first lens element 10. When light emitted or reflected by
an object (not shown) which is located at the object side 2 enters
the optical imaging lens set 1 of the present invention, it forms a
clear and sharp image on the image plane 71 at the image side 3
after passing through the aperture stop 80, the first lens element
10, the second lens element 20, the third lens element 30, the
fourth lens element 40, the fifth lens element 50, the sixth lens
element 60 and the filter 70. In one embodiments of the present
invention, the optional filter 70 may be a filter of various
suitable functions, for example, the filter 70 may be an infrared
cut filter (IR cut filter), placed between the sixth lens element
60 and the image plane 71. The filter 70 may be made of glass.
[0085] Each lens element in the optical imaging lens set 1 of the
present invention has an object-side surface facing toward the
object side 2 as well as an image-side surface facing toward the
image side 3. For example, the first lens element 10 has a first
object-side surface 11 and a first image-side surface 12; the
second lens element 20 has a second object-side surface 21 and a
second image-side surface 22; the third lens element 30 has a third
object-side surface 31 and a third image-side surface 32; the
fourth lens element 40 has a fourth object-side surface 41 and a
fourth image-side surface 42; the fifth lens element 50 has a fifth
object-side surface 51 and a fifth image-side surface 52; the sixth
lens element 60 has a sixth object-side surface 61 and a sixth
image-side surface 62. In addition, each object-side surface and
image-side surface in the optical imaging lens set 1 of the present
invention has a part (or portion) in a vicinity of its circular
periphery (circular periphery part) away from the optical axis 4 as
well as a part in a vicinity of the optical axis (optical axis
part) close to the optical axis 4.
[0086] Each lens element in the optical imaging lens set 1 of the
present invention further has a central thickness on the optical
axis 4. For example, the first lens element 10 has a first lens
element thickness T.sub.1, the second lens element 20 has a second
lens element thickness T.sub.2, the third lens element 30 has a
third lens element thickness T.sub.3, the fourth lens element 40
has a fourth lens element thickness T.sub.4, the fifth lens element
50 has a fifth lens element thickness T.sub.5, the sixth lens
element 60 has a sixth lens element thickness T.sub.6. Therefore,
the total thickness of all the lens elements in the optical imaging
lens set 1 along the optical axis 4 is
ALT=T.sub.1+T.sub.2+T.sub.3+T.sub.4+T.sub.5+T.sub.6.
[0087] In addition, between two adjacent lens elements in the
optical imaging lens set 1 of the present invention there is an air
gap along the optical axis 4. For example, an air gap G.sub.12 is
disposed between the first lens element 10 and the second lens
element 20, an air gap G.sub.23 is disposed between the second lens
element 20 and the third lens element 30, an air gap G.sub.34 is
disposed between the third lens element 30 and the fourth lens
element 40, an air gap G.sub.45 is disposed between the fourth lens
element 40 and the fifth lens element 50 as well as an air gap
G.sub.56 is disposed between the fifth lens element 50 and the
sixth lens element 60. Therefore, the sum of total three air gaps
between adjacent lens elements from the first lens element 10 to
the sixth lens element 60 along the optical axis 4 is
AAG=G.sub.12+G.sub.23+G.sub.34+G.sub.45+G.sub.56.
[0088] In addition, the distance between the first object-side
surface 11 of the first lens element 10 to the image plane 71,
namely the total length of the optical imaging lens set along the
optical axis 4 is TTL; the effective focal length of the optical
imaging lens set is EFL; the distance between the sixth image-side
surface 62 of the sixth lens element 60 to the image plane 71 along
the optical axis 4 is BFL.
[0089] Furthermore, the focal length of the first lens element 10
is f1; the focal length of the second lens element 20 is f2; the
focal length of the third lens element 30 is f3; the focal length
of the fourth lens element 40 is f4; the focal length of the fifth
lens element 50 is f5; the focal length of the sixth lens element
60 is f6; the refractive index of the first lens element 10 is n1;
the refractive index of the second lens element 20 is n2; the
refractive index of the third lens element 30 is n3; the refractive
index of the fourth lens element 40 is n4; the refractive index of
the fifth lens element 50 is n5; the refractive index of the sixth
lens element 60 is n6; the Abbe number of the first lens element 10
is u1; the Abbe number of the second lens element 20 is u2; the
Abbe number of the third lens element 30 is u3; and the Abbe number
of the fourth lens element 40 is u4; the Abbe number of the fifth
lens element 50 is u5; and the Abbe number of the sixth lens
element 60 is u6.
First Example
[0090] Please refer to FIG. 6 which illustrates the first example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 7A for the longitudinal spherical aberration on the
image plane 71 of the first example; please refer to FIG. 7B for
the astigmatic field aberration on the sagittal direction; please
refer to FIG. 7C for the astigmatic field aberration on the
tangential direction, and please refer to FIG. 7D for the
distortion aberration. The Y axis of the spherical aberration in
each example is "field of view" for 1.0. The Y axis of the
astigmatic field and the distortion in each example stand for "Half
Field of View (HFOV)", HFOV stands for the half field of view which
is half of the field of view of the entire optical lens element
system. The Y axis of the astigmatic field and the distortion in
each example stands for "image height", which is 3 mm.
[0091] The optical imaging lens set 1 of the first example has six
lens elements 10 to 60 made of a plastic material and having
refractive power. The optical imaging lens set 1 also has an
aperture stop 80, a filter 70, and an image plane 71. The aperture
stop 80 is provided between the object side 2 and the first lens
element 10. The filter 70 may be used for preventing specific
wavelength light (such as the infrared light) reaching the image
plane to adversely affect the imaging quality.
[0092] The first lens element 10 has positive refractive power. The
first object-side surface 11 facing toward the object side 2 is a
convex surface, having a convex part 13 in the vicinity of the
optical axis and a convex part 14 in a vicinity of its circular
periphery. The first image-side surface 12 facing toward the image
side 3 is a convex surface, having a convex part 16 in the vicinity
of the optical axis and a convex part 17 in a vicinity of its
circular periphery. Besides, both the first object-side surface 11
and the first image-side 12 of the first lens element 10 are
aspherical surfaces.
[0093] The second lens element 20 has negative refractive power.
The second object-side concave surface 21 facing toward the object
side 2 has a concave part 23 in the vicinity of the optical axis
and a concave part 24 in a vicinity of its circular periphery. The
second image-side surface 22 facing toward the image side 3 has a
concave part 26 in the vicinity of the optical axis and a convex
part 27 in a vicinity of its circular periphery. Both the second
object-side surface 21 and the second image-side 22 of the second
lens element 20 are aspherical surfaces.
[0094] The third lens element 30 has positive refractive power. The
third object-side surface 31 facing toward the object side 2 has a
convex part 33 in the vicinity of the optical axis and a concave
part 34 in a vicinity of its circular periphery. The third
image-side surface 32 facing toward the image side 3 has a concave
part 36 in the vicinity of the optical axis and a convex part 37 in
a vicinity of its circular periphery. Both the third object-side
surface 31 and the third image-side 32 of the third lens element 30
are aspherical surfaces.
[0095] The fourth lens element 40 has positive refractive power.
The fourth object-side surface 41 facing toward the object side 2
has a concave part 43 in the vicinity of the optical axis and a
concave part 44 in a vicinity of its circular periphery. The fourth
image-side surface 42 facing toward the image side 3 has a convex
part 46 in the vicinity of the optical axis and a concave part 47
in a vicinity of its circular periphery. Both the fourth
object-side surface 41 and the fourth image-side 42 of the fourth
lens element 40 are aspherical surfaces.
[0096] The fifth lens element 50 has positive refractive power. The
fifth object-side surface 51 facing toward the object side 2 has a
convex part 53 in the vicinity of the optical axis and a concave
part 54 in a vicinity of its circular periphery. The fifth
image-side surface 52 facing toward the image side 3 has a convex
part 56 in the vicinity of the optical axis and a convex part 57 in
a vicinity of its circular periphery. Both the fifth object-side
surface 51 and the fifth image-side 52 of the fifth lens element 50
are aspherical surfaces.
[0097] The sixth lens element 60 has negative refractive power. The
concave sixth object-side surface 61 facing toward the object side
2 has a concave part 63 in the vicinity of the optical axis and a
concave part 64 in a vicinity of its circular periphery. The sixth
image-side surface 62 facing toward the image side 3 has a concave
part 66 in the vicinity of the optical axis and a convex part 67 in
a vicinity of its circular periphery. Both the sixth object-side
surface 61 and the sixth image-side 62 of the sixth lens element 60
are aspherical surfaces. The filter 70 may be disposed between the
sixth image-side 62 of the sixth lens element 60 and the image
plane 71.
[0098] In the first lens element 10, the second lens element 20,
the third lens element 30, the fourth lens element 40, the fifth
lens element 50 and the sixth lens element 60 of the optical
imaging lens element 1 of the present invention, the object-side
surfaces 11/21/31/41/51/61 and image-side surfaces
12/22/32/42/52/62 are all aspherical. These aspheric coefficients
are defined according to the following formula:
Z ( Y ) = Y 2 R / ( 1 + 1 - ( 1 + K ) Y 2 R 2 ) + i = 1 n a 2 i
.times. Y 2 i ##EQU00001##
In which: R represents the curvature radius of the lens element
surface; Z represents the depth of an aspherical surface (the
perpendicular distance between the point of the aspherical surface
at a distance Y from the optical axis and the tangent plane of the
vertex on the optical axis of the aspherical surface); Y represents
a vertical distance from a point on the aspherical surface to the
optical axis; K is a conic constant; a.sub.21 is the aspheric
coefficient of the 2i order.
[0099] The optical data of the first example of the optical imaging
lens set 1 are shown in FIG. 22 while the aspheric surface data are
shown in FIG. 23. In the present examples of the optical imaging
lens set, the f-number of the entire optical lens element system is
Fno, HFOV stands for the half field of view which is half of the
field of view of the entire optical lens element system, and the
unit for the curvature radius, the thickness and the focal length
is in millimeters (mm). The image height is 3 mm. HFOV is 39.483
degrees. Some important ratios of the first example are as
follows:
EFL/T.sub.1=5.261
[0100] T.sub.6/G.sub.34=2.358
ALT/G.sub.34=9.957
BFL/T.sub.2=4.628
[0101] T.sub.2/T.sub.6=0.451 T.sub.5/T.sub.1=0.433
EFL/T.sub.2=12.141
[0102] T.sub.1/T.sub.3=1.670
ALT/T.sub.1=4.054
EFL/G.sub.34=12.922
[0103] AAG/(G.sub.45+G.sub.56)=3.273 T.sub.5/T.sub.6=0.451
EFL/T.sub.4=8.374
[0104] T.sub.5/T.sub.4=0.690
ALT/T.sub.4=6.452
Second Example
[0105] Please refer to FIG. 8 which illustrates the second example
of the optical imaging lens set 1 of the present invention. It is
noted that from the second example to the following examples, in
order to simplify the figures, only the components different from
what the first example has, and the basic lens elements will be
labeled in figures. Other components that are the same as what the
first example has, such as the object-side surface, the image-side
surface, the part in a vicinity of the optical axis and the part in
a vicinity of its circular periphery will be omitted in the
following examples. Please refer to FIG. 9A for the longitudinal
spherical aberration on the image plane 71 of the second example,
please refer to FIG. 9B for the astigmatic aberration on the
sagittal direction, please refer to FIG. 9C for the astigmatic
aberration on the tangential direction, and please refer to FIG. 9D
for the distortion aberration. The components in the second example
are similar to those in the first example, but the optical data
such as the curvature radius, the refractive power, the lens
thickness, the lens focal length, the aspheric surface or the back
focal length in this example are different from the optical data in
the first example, and in this example, the fourth object-side
surface 41 has a concave part 43 in the vicinity of the optical
axis and a convex part 44' in a vicinity of its circular periphery.
The optical data of the second example of the optical imaging lens
set are shown in FIG. 24 while the aspheric surface data are shown
in FIG. 25. The image height is 3 mm. HFOV is 40.405 degrees.
[0106] Some important ratios of the second example are as
follows:
EFL/T.sub.1=5.421
[0107] T.sub.6/G.sub.34=1.461
ALT/G.sub.34=12.560
BFL/T.sub.2=4.955
[0108] T.sub.2/T.sub.6=0.880 T.sub.5/T.sub.1=1.019
EFL/T.sub.2=11.759
[0109] T.sub.1/T.sub.3=1.488
ALT/T.sub.1=4.502
EFL/G.sub.34=15.125
[0110] AAG/(G.sub.45+G.sub.56)=4.753 T.sub.5/T.sub.6=1.947
EFL/T.sub.4=6.566
[0111] T.sub.5/T.sub.4=1.235
ALT/T.sub.4=5.452
Third Example
[0112] Please refer to FIG. 10 which illustrates the third example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 11A for the longitudinal spherical aberration on the
image plane 71 of the third example; please refer to FIG. 11B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 11C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 11D for the distortion
aberration. The components in the third example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example. The optical data of the third example of the optical
imaging lens set are shown in FIG. 26 while the aspheric surface
data are shown in FIG. 27. The image height is 3 mm. HFOV is 39.968
degrees. Some important ratios of the third example are as
follows:
EFL/T.sub.1=7.495
[0113] T.sub.6/G.sub.34=1.427
ALT/G.sub.34=11.402
BFL/T.sub.2=5.761
[0114] T.sub.2/T.sub.6=1.000 T.sub.5/T.sub.1=0.627
EFL/T.sub.2=11.956
[0115] T.sub.1/T.sub.3=1.378
ALT/T.sub.1=5.008
EFL/G.sub.34=17.065
[0116] AAG/(G.sub.45+G.sub.56)=2.410 T.sub.5/T.sub.6=1.000
EFL/T.sub.4=5.349
[0117] T.sub.5/T.sub.4=0.447
[0118] ALT/T.sub.4=3.574
Fourth Example
[0119] Please refer to FIG. 12 which illustrates the fourth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 13A for the longitudinal spherical aberration on the
image plane 71 of the fourth example; please refer to FIG. 13B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 13C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 13D for the distortion
aberration. The components in the fourth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the third object-side surface 31 of
the third lens element 30 has a convex part 33 in the vicinity of
the optical axis, a convex part 34' in a vicinity of its circular
periphery and a concave part 35 between the optical axis and the
circular periphery part, and the third image-side surface 32 has a
concave part 36 in the vicinity of the optical axis, a concave part
37' in a vicinity of its circular periphery and a convex part 38
between the optical axis and the circular periphery part. The
optical data of the fourth example of the optical imaging lens set
are shown in FIG. 28 while the aspheric surface data are shown in
FIG. 29. The image height is 3 mm. HFOV is 40.150 degrees. Some
important ratios of the fourth example are as follows:
EFL/T.sub.1=6.416
[0120] T.sub.6/G.sub.34=1.339
ALT/G.sub.34=13.178
BFL/T.sub.2=2.096
[0121] T.sub.2/T.sub.6=2.131 T.sub.5/T.sub.1=1.011
EFL/T.sub.2=5.559
[0122] T.sub.1/T.sub.3=1.411
ALT/T.sub.1=5.331
EFL/G.sub.34=15.860
[0123] AAG/(G.sub.45+G.sub.56)=2.555 T.sub.5/T.sub.6=1.866
EFL/T.sub.4=7.003
[0124] T.sub.5/T.sub.4=1.103
ALT/T.sub.4=5.819
Fifth Example
[0125] Please refer to FIG. 14 which illustrates the fifth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 15A for the longitudinal spherical aberration on the
image plane 71 of the fifth example; please refer to FIG. 15B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 15C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 15D for the distortion
aberration. The components in the fifth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example. The optical data of the fifth example of the optical
imaging lens set are shown in FIG. 30 while the aspheric surface
data are shown in FIG. 31. The image height is 3 mm. HFOV is 39.529
degrees. Some important ratios of the fifth example are as
follows:
EFL/T.sub.1=3.915
[0126] T.sub.6/G.sub.34=1.262
ALT/G.sub.34=11.845
BFL/T.sub.2=5.066
[0127] T.sub.2/T.sub.6=1.000 T.sub.5/T.sub.1=0.507
EFL/T.sub.2=12.130
[0128] T.sub.1/T.sub.3=2.765
ALT/T.sub.1=3.029
EFL/G.sub.34=15.307
[0129] AAG/(G.sub.45+G.sub.56)=3.059 T.sub.6/T.sub.6=1.570
EFL/T.sub.4=7.594
[0130] T.sub.6/T.sub.4=0.983
ALT/T.sub.4=5.876
Sixth Example
[0131] Please refer to FIG. 16 which illustrates the sixth example
of the optical imaging lens set 1 of the present invention. Please
refer to FIG. 17A for the longitudinal spherical aberration on the
image plane 71 of the sixth example; please refer to FIG. 17B for
the astigmatic aberration on the sagittal direction; please refer
to FIG. 17C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 17D for the distortion
aberration. The components in the sixth example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the third object-side surface 31 of
the third lens element 30 has a convex part 33 in the vicinity of
the optical axis, a convex part 34' in a vicinity of its circular
periphery and a concave part 35 between the optical axis and the
circular periphery part. The optical data of the sixth example of
the optical imaging lens set are shown in FIG. 32 while the
aspheric surface data are shown in FIG. 33. The image height is 3
mm. HFOV is 40.216 degrees. Some important ratios of the sixth
example are as follows:
EFL/T.sub.1=7.468
[0132] T.sub.6/G.sub.34=1.438
ALT/G.sub.34=13.816
BFL/T.sub.2=2.003
[0133] T.sub.2/T.sub.6=2.089 T.sub.5/T.sub.1=1.371
EFL/T.sub.2=5.402
[0134] T.sub.1/T.sub.3=1.195
ALT/T.sub.1=6.357
EFL/G.sub.34=16.229
[0135] AAG/(G.sub.45+G.sub.56)=2.622 T.sub.5/T.sub.6=2.071
EFL/T.sub.4=6.757
[0136] T.sub.5/T.sub.4=1.240
ALT/T.sub.4=5.752
Seventh Example
[0137] Please refer to FIG. 18 which illustrates the seventh
example of the optical imaging lens set 1 of the present invention.
Please refer to FIG. 19A for the longitudinal spherical aberration
on the image plane 71 of the seventh example; please refer to FIG.
19B for the astigmatic aberration on the sagittal direction; please
refer to FIG. 19C for the astigmatic aberration on the tangential
direction, and please refer to FIG. 19D for the distortion
aberration. The components in the seventh example are similar to
those in the first example, but the optical data such as the
curvature radius, the refractive power, the lens thickness, the
lens focal length, the aspheric surface or the back focal length in
this example are different from the optical data in the first
example, and in this example, the second object-side surface 21 of
the second lens element 20 has a convex part 23' in the vicinity of
the optical axis and a concave part 24 in a vicinity of its
circular periphery, the third object-side surface 31 of the third
lens element 30 has a concave part 33' in the vicinity of the
optical axis and a convex part 34' in a vicinity of its circular
periphery. The third image-side surface 32 has a convex part 36' in
the vicinity of the optical axis and a concave part 37' in a
vicinity of its circular periphery. The optical data of the seventh
example of the optical imaging lens set are shown in FIG. 34 while
the aspheric surface data are shown in FIG. 35. The image height is
3 mm. HFOV is 39.896 degrees. Some important ratios of the seventh
example are as follows:
EFL/T.sub.1=5.864
[0138] T.sub.6/G.sub.34=2.281
ALT/G.sub.34=18.682
BFL/T.sub.2=5.564
[0139] T.sub.2/T.sub.6=0.920 T.sub.5/T.sub.1=0.975
EFL/T.sub.2=11.980
[0140] T.sub.1/T.sub.3=1.666
ALT/T.sub.1=4.358
EFL/G.sub.34=25.142
[0141] AAG/(G.sub.45+G.sub.56)=3.041 T.sub.5/T.sub.6=1.833
EFL/T.sub.4=7.708
[0142] T.sub.5/T.sub.4=1.282
ALT/T.sub.4=5.728
[0143] Some important ratios in each example are shown in FIG. 36.
The distance between the sixth image-side surface 62 of the sixth
lens element 60 to the filter 70 along the optical axis 4 is G6F;
the thickness of the filter 70 along the optical axis 4 is TF; the
distance between the filter 70 to the image plane 71 along the
optical axis 4 is GFI; the distance between the sixth image-side
surface 62 of the sixth lens element 60 to the image plane 71 along
the optical axis 4 is BFL. Therefore, BFL=G6F+TF+GFI.
[0144] In the light of the above examples, the inventors observe
the following features:
1. The first image-side surface with a convex part in a vicinity of
its circular periphery, the second image-side surface with a
concave part in the vicinity of the optical axis and with a convex
part in a vicinity of its circular periphery, the fourth image-side
surface with a concave part in a vicinity of its circular periphery
and the sixth object-side surface with a concave part in the
vicinity of the optical axis together help correct the aberration
and improve the imaging quality. 2. The third lens element 30, the
fifth lens element 50 and the sixth lens element 60 which are made
of a plastic material are advantageous to the reduction of the
weight of the lens elements and the cost for production. 3. The
aperture stop is disposed in front of the first lens element to
improve the imaging quality and to decrease the length of the
optical imaging lens set. 4. With the further help of a convex part
in a vicinity of the optical axis and its circular periphery of the
first object-side surface, of a convex part in a vicinity of the
optical axis of the first image-side surface, a concave part in a
vicinity of its circular periphery of the second object-side
surface, a concave part in a vicinity of the optical axis of the
fourth object-side surface, a convex part in a vicinity of its
circular periphery of the fourth image-side surface, a concave part
in a vicinity of its circular periphery and a convex part in a
vicinity of the optical axis of the fifth object-side surface, a
convex part in a vicinity of its circular periphery and in a
vicinity of the optical axis of the fifth image-side surface, a
concave part in a vicinity of its circular periphery of the sixth
object-side surface, and a convex part in a vicinity of its
circular periphery and a concave part in a vicinity of the optical
axis of the sixth image-side surface, it ensures a good imaging
quality while decreasing the total length of the optical imaging
lens set. Furthermore, if all of the lens elements are made of a
plastic material, this can further help to decrease the
manufacturing cost and the weight to form the aspherical
surface.
[0145] In addition, the inventors discover that there are some
better ratio ranges for different data according to the above
various important ratios. Better ratio ranges help the designers to
design a better optical performance and an effectively reduce
length of a practically possible optical imaging lens set. For
example:
(1) Since the lens element becomes lighter and thinner, and the
imaging quality demands get higher and higher, so that the lens is
designed to have different shape surface in a vicinity of the
optical axis and in vicinity of its circular periphery, the
thickness is different in the central part of the lens element or
near the edge of the lens element. Considering the characteristics
of light, the light which is emitted from the near-edge side of the
lens element has the longer path and larger refraction angle to
focus onto the image plane. EFL is related to the thickness of each
lens element and the air gaps, and BFL is also dependent on EFL so
the following relationships are proposed to effectively reduce the
total length while keeping a good imaging quality.
EFL/T.sub.1.ltoreq.7.5
BFL/T.sub.2.ltoreq.5.77
[0146] 0.45.ltoreq.T.sub.2/T.sub.6 T.sub.5/T.sub.1.ltoreq.1.4
EFL/T.sub.2.ltoreq.16
[0147] 1.ltoreq.T.sub.1/T.sub.3
ALT/T.sub.1.ltoreq.7
[0148] 2.41.ltoreq.AAG/(G.sub.45+G.sub.56)
T.sub.5/T.sub.6.ltoreq.2.08
EFL/T.sub.4.ltoreq.9.38
[0149] T.sub.5/T.sub.4.ltoreq.1.29
ALT/T.sub.4.ltoreq.6.5
[0150] (2) The shape of the third image-side surface and the fourth
object-side surface are not specifically specified so they can be
much more reduced in length to facilitate the total reduction of
the optical lens set. However, it is still needed to keep G.sub.34
to have a certain width to facilitate the assembly of the optical
lens set. The following relationship are suggested to have a better
manufacturing yield: T.sub.6/G.sub.34.ltoreq.4
ALT/G.sub.34.ltoreq.19
EFL/G.sub.34.ltoreq.25.1
[0151] (3) To obtain a better imaging quality and to facilitate the
fabrication of the optical lens set, and the arrangement of the
thickness and gaps, the following relationships are suggested:
3.5.ltoreq.EFL/T.sub.1.ltoreq.7.5
[0152] 0.8.ltoreq.T.sub.6/G.sub.34.ltoreq.4
9.ltoreq.ALT/G.sub.34.ltoreq.19
1.8.ltoreq.BFL/T.sub.2.ltoreq.5.77
[0153] 0.45.ltoreq.T.sub.2/T.sub.6.ltoreq.2.25
0.3.ltoreq.T.sub.5/T.sub.1.ltoreq.1.4
5.ltoreq.EFL/T.sub.2.ltoreq.16
[0154] 1.ltoreq.T.sub.1/T.sub.3.ltoreq.3.2
2.5.ltoreq.ALT/T.sub.1.ltoreq.7
10.ltoreq.EFL/G.sub.34.ltoreq.25.2
[0155] 2.41.ltoreq.AAG/(G.sub.45+G.sub.56).ltoreq.4
0.3.ltoreq.T.sub.5/T.sub.6.ltoreq.2.08
4.8.ltoreq.EFL/T.sub.4.ltoreq.9.38
[0156] 0.3.ltoreq.T.sub.5/T.sub.4.ltoreq.1.29
3.ltoreq.ALT/T.sub.4.ltoreq.6.5
[0157] The optical imaging lens set 1 of the present invention may
be applied to an electronic device, such as mobile phones or
driving recorders. Please refer to FIG. 20. FIG. 20 illustrates a
first preferred example of the optical imaging lens set 1 of the
present invention for use in a portable electronic device 100. The
electronic device 100 includes a case 110, and an image module 120
mounted in the case 110. A driving recorder is illustrated in FIG.
20 as an example, but the electronic device 100 is not limited to a
driving recorder.
[0158] As shown in FIG. 20, the image module 120 includes the
optical imaging lens set 1 as described above. FIG. 20 illustrates
the aforementioned first example of the optical imaging lens set 1.
In addition, the portable electronic device 100 also contains a
barrel 130 for the installation of the optical imaging lens set 1,
a module housing unit 140 for the installation of the barrel 130, a
substrate 172 for the installation of the module housing unit 140
and an image sensor 70 disposed at the substrate 172, and at the
image side 3 of the optical imaging lens set 1. The image sensor 70
in the optical imaging lens set 1 may be an electronic
photosensitive element, such as a charge coupled device or a
complementary metal oxide semiconductor element. The image plane 71
forms at the image sensor 70.
[0159] The image sensor 70 used here is a product of chip on board
(COB) package rather than a product of the conventional chip scale
package (CSP) so it is directly attached to the substrate 172, and
protective glass is not needed in front of the image sensor 70 in
the optical imaging lens set 1, but the present invention is not
limited to this.
[0160] To be noticed in particular, the optional filter 70 may be
omitted in other examples although the optional filter 70 is
present in this example. The case 110, the barrel 130, and/or the
module housing unit 140 may be a single element or consist of a
plurality of elements, but the present invention is not limited to
this.
[0161] Each one of the six lens elements 10, 20, 30, 40, 50 and 60
with refractive power is installed in the barrel 130 with air gaps
disposed between two adjacent lens elements in an exemplary way.
The module housing unit 140 has a lens element housing 141, and an
image sensor housing 146 installed between the lens element housing
141 and the image sensor 70. However in other examples, the image
sensor housing 146 is optional. The barrel 130 is installed
coaxially along with the lens element housing 141 along the axis
I-I', and the barrel 130 is provided inside of the lens element
housing 141.
[0162] Please also refer to FIG. 21 for another application of the
aforementioned optical imaging lens set 1 in a portable electronic
device 200 in the second preferred example. The main differences
between the portable electronic device 200 in the second preferred
example and the portable electronic device 100 in the first
preferred example are: the lens element housing 141 has a first
seat element 142, a second seat element 143, a coil 144 and a
magnetic component 145. The first seat element 142 is for the
installation of the barrel 130, exteriorly attached to the barrel
130 and disposed along the axis I-I'. The second seat element 143
is disposed along the axis I-I' and surrounds the exterior of the
first seat element 142. The coil 144 is provided between the
outside of the first seat element 142 and the inside of the second
seat element 143. The magnetic component 145 is disposed between
the outside of the coil 144 and the inside of the second seat
element 143.
[0163] The first seat element 142 may pull the barrel 130 and the
optical imaging lens set 1 which is disposed inside of the barrel
130 to move along the axis I-I', namely the optical axis 4 in FIG.
6. The image sensor housing 146 is attached to the second seat
element 143. The filter 70, such as an infrared filter, is
installed at the image sensor housing 146. Other details of the
portable electronic device 200 in the second preferred example are
similar to those of the portable electronic device 100 in the first
preferred example so they are not elaborated again.
[0164] Those skilled in the art will readily observe that numerous
modifications and alterations of the device and method may be made
while retaining the teachings of the invention. Accordingly, the
above disclosure should be construed as limited only by the metes
and bounds of the appended claims.
* * * * *